Pope Francis's critique of free-market economics has made him an icon for the Left and prompted claims that he is a communist. The leader of the world's 1.2 billion Catholics has called capitalism a source of inequality at best - and at worst a killer. Is the Pope, as his critics claim, a red radical?

On his way back from the Victory Day Parade in Moscow last month, the Cuban leader Raul Castro stopped off in Rome to thank Pope Francis for his role in Cuba's rapprochement with the United States. "If the Pope continues this way," Castro said afterwards, "I will go back to praying and go back to the church - I am not joking."

In September Francis will return the compliment with a stop-over in Cuba when he travels to the United States. And the American visit could turn out to be the most difficult overseas trip of his pontificate.

Raul Castro's endorsement is unlikely to recommend Francis to the American right, many of whom responded with visceral rage to President Obama's Cuban initiative.

Raul Castro and Pope Francis in the Vatican, May 2015

"There is a lot of scepticism among (US) Catholics," says Stephen Moore, the chief economist at the conservative Washington think tank the Heritage Foundation, and himself a Catholic.

"I think this is a Pope who clearly has some Marxist leanings. It's unquestionable that he has a very vocal scepticism (about) capitalism and free enterprise and… I find that to be very troubling."

Find out more

Ed Stourton's report, Is The Pope A Communist? can be heard on Analysis, on Monday 8 June at 20:30 BST on Radio 4

Rush Limbaugh, the conservative radio host (or "shock jock", as he is sometimes called) is blunter. He dismissed Pope Francis's apostolic exhortationEvangelii Gaudium (The Joy of the Gospels) as "pure Marxism".

The US is far and away the Western world's most Christian nation. There are nearly 80 million baptised American Catholics, and it is the country's largest religious denomination. Many of its members look upon Saint John Paul II as a hero-pope because he was such a doughty Cold Warrior - and that adds the spice of a sense of betrayal to their reaction to Francis. Although his approval ratings are high, particularly among Catholic Democrats, he will be a polarising presence, and the question "Is the pope a communist?" will really matter.

Popes John Paul and Francis came from very different worlds, and that inevitably influenced their thinking on issues like the economy and social justice.

Pope John Paul II's attitude to communism was shaped by his time living in totalitarian regimes

Most of John Paul's early life was lived under totalitarian regimes - first the Nazi occupation during World War Two, then the long Stalinist and Soviet domination of Poland during the Cold War. Everything he experienced as a priest and a bishop taught him that communism was the enemy.

By contrast, Francis - or Jorge Bergoglio as he then was - came of age under the regime of the nationalist Argentine leader, Juan Peron.

Austen Ivereigh, who has written a biography of Pope Francis, and himself studied theology in Argentina, says Peronism has dominated Argentine politics ever since but is difficult to define in conventional political terms.

"It is really neither left wing nor right wing," he says. "But it comes out of a kind of nationalist revival in Argentina in the 1930s and 1940s and was very closely identified with the working class, above all, and particularly the trade unions." Ivereigh believes the young Bergoglio was profoundly influenced by Peronist ideas.

Juan Peron 1895-1976

Elected president of Argentina three times - twice between 1946 and 1955 and also 1973-74

Gave rise to Peronism, a political movement which defines itself by three aims - social justice, economic independence, and political sovereignty

Peron's first wife Eva (pictured with him, above, in 1950) was the subject of the musical, Evita

The two Popes also had a very different understanding of Liberation Theology, the controversial movement based on the conviction that the gospels enjoin the Church to put the poor first, which preoccupied and divided Latin America's Catholics for much of the 1960s, 70s, and 80s. John Paul believed it had tempted some priests and bishops into quasi-Marxist and even violent ideology, and as Pope he cracked down on some Liberation Theologians. Jorge Bergolio rejected Marxism - although he cheerfully accepts that he has many Marxist friends - but accepted many of Liberation Theology's principles, espousing what Austen Ivereigh calls "a nationalist version" of the movement, or a so-called "Theology of the People".

Nonetheless, the economic writings of both John Paul and Francis also reflect the same intellectual tradition - one known as Catholic Social Teaching. It was originally articulated in an 1881 papal document called Rerum Novarum, in which Pope Leo XIII addressed what he called the "spirit of revolutionary change" then sweeping Europe.

Some of it is very clearly designed to be a rebuttal of the communist ideas that were part of that change, but it is also a critique of aspects of capitalism. So it is an unfamiliar mix that does not fit neatly into the left-right divide that dominated the politics of the following century.

Prof Maurice Glasman, a British economist who used to be a close confidant of Ed Miliband, studied Catholic social teaching for his PhD. He was attracted by the way it rejects the conventional ideologies of both left and right.

"It really opposes this idea that there is just the state or the market," he says. "It believes in activating society - what it calls solidarity - so that it can resist the domination by the rich of the poor, but through trade unions and vocational associations and what's called subsidiarity, which is the decentralisation of power." Glasman says it is opposed to communism because it "upholds private property" and is "anti-collectivist".

Glasman has a vivid memory of being attacked by an American economist after giving a paper at a recent Vatican conference on Catholic social teaching. "You know there's a word for what you're saying, Baron Lord Professor or whatever you are," the challenge began. "Yeah, it's called Communism. You're trying to interfere with the prerogatives of management, you're trying to interfere with capital, and you're trying to interfere with prices. And that's been tried - and that's the Soviet Union."

During the subsequent discussion Glasman was delighted to find himself supported by both the Pope and the Archbishop of Munich, the appropriately named Cardinal Marx.

Francis' interpretation of Catholic social teaching certainly sounds more radical than that of his predecessors. In Argentina he insisted that his priests should see the world through the eyes of the poor, by living among them, and he brought that approach with him to Rome. Evangelii Gaudium - the document which got Rush Limbaugh so worked up - argues that inequality creates "a state of social sin that cries to Heaven". Pope Frances has also said that unemployment is "the result of a worldwide choice, of an economic system that led to this tragedy, an economic system that has at its centre a false God, a false God called money".

Philip Booth, a Catholic economist who works at the London free-market think tank the Institute for Economic Affairs, suggests Francis's views are close to those of the Guardian columnist Polly Toynbee and the left-wing French economist Thomas Piketty, whose book on inequality became an international bestseller last year.

He describes Francis as a "corporatist" who believes in a big state, and argues the Pope's statements are "dangerous" because they could "lead us to bad policy".

The answer to the question posed in the title of this piece is "No". There is lots for those on the left to admire in Pope Francis, and lots for those on the right to be scandalised by, but he is not a communist.

He does, however, seem to enjoy provoking people. He will soon publish an encyclical expected to deal with climate change, and a priest who has been briefed on the contents told us "If some people think that he's a Marxist (now), wait and see what he says on the environment!"

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